The invention relates to a storage system and a power consumption reduction method, and an information processing apparatus, and is suitable for use in, for example, an archive system for storing data sent from a host computer.
In general, an archive system is composed of host computers for separately conducting their operations and an archive apparatus for conducting read/write of data according to commands from each of the host computers. The archive apparatus is composed of a computer called an archive node (information processing apparatus) and a storage apparatus for conducting read/write of data according to a command from the archive node. The archive apparatus provides the host computer with storage areas. The archive node commands the storage apparatus to conduct read/write of data upon receiving a command to conduct read/write of data from the host computer. The storage apparatus divides a physical disk into plural storage areas for management, and provides the storage areas as logical volumes to the archive node. Each logical volume is composed of plural segments. Each storage area on a physical disk is assigned to each segment, which enables read/write of data according to the command from the host computer.
For example, disclosed in WO 2005/043323, Pamphlet is a dispersion archive technique in which: a cluster is composed of plural archive nodes in an archive apparatus; archive data is written to the archive nodes in accordance with redundancy specified by a host computer; and in this way, the host computer can access the archive data even when errors occur in parts of the archive nodes.
Also, JP2000-293314 A discloses a power-saving technique in which, when there is no access to all the logical volumes constituted by specific hard disks for a fixed period in a storage apparatus, the power supply of each of the hard disks constituting the logical volumes is interrupted or put into a power saving mode.
However, the following problem arises when the dispersion archive technique in prior art is combined with a power saving technique, thereby reducing power consumption of a storage system in an archive system, which utilizes the dispersion archive technique by using the power saving technique.
In the dispersion archive technique, the archive data written to the archive system is distributed to the archive nodes constituting the cluster.
Therefore, the archive nodes access the logical volume in the storage apparatus with roughly the same frequency so the period during which there is no access to the logical volume is shortened.
Accordingly, a problem arises in that the move to the interruption or the power saving mode for the power supply of each of the hard disks constituting the logical volumes cannot be realized, which means that the reduction of power consumption in the storage apparatus cannot be achieved.